The invention relates to an endoscope, particularly a flexible endoscope with the features of the preamble of claim 1.
Endoscopes of this kind, for example duodenoscopes, whose lens is usually arranged at the side of the endoscope head, comprise a mechanism, in particular an Albarran mechanism with an Albarran lever, which makes it possible to move the probes, which are introduced into the endoscpoe through the working channel thereof, in the angle of view of the lens. The Albarran lever can be moved by means of a Bowden wire device extending between the distal and the proximal ends via an operating lever arranged at the outside of the endoscope""s housing.
In commonly known endoscopes of the type described in the document U.S. Pat. No. 4,198,959, the Albarran mechanism or the Albarran lever is a fixedly integrated component of the endoscope head, and the sheathing of the Bowden wire device is embodied as a channel in the endoscope""s introduction shaft and housing, which is sealed off from the inside of the endoscope. The traction wire of the Bowden wire device extending therethrough is usually sealed off from the outside at the distal and the proximal ends of the Bowden wire device with the aid of sealing rings. As these seals are seals through which a movable wire extends, at least the distal end may be contaminated as a result of pulling a piece of wire which is soiled e.g. with blood to the inside when an endoscope of this kind is used. Endoscopes or heads of endoscopes soiled in such a manner are difficult to clean and, when used again, lead to problems regarding hygiene or to spreading of germs and to increased sluggishness of the Bowden wire device or of the entire operating mechanism of the Albarran lever.
In another type of endoscope, the Bowden wire device can be irrigated for cleaning purposes through an opening for a syringe at the proximal end thereof. During irrigation, the liquid can emerge at the distal end of the Bowden wire device, which is not sealed. In case of inexpert handling, however, some of the irrigation liquid may leak into the inside of the endoscope as a result of too high pressure exerted on the inner seals. Mostly, such cases occurring in practice result from already existing contamination which causes a reduction of the cross-section of the channel to be irrigated and thus a lower rate of flow; here, the maximum permissible pressure may easily be exceeded if the operating personnel exerts too much pressure on the syringe. As a consequence of this, the endoscope will have to be repaired, which is both time-consuming and expensive.
Furthermore, both these known types share the disadvantage that the Albarran mechanism is difficult to clean because of the fact that it is integrated in the instrument. In practice, this mechanism has to be cleaned with a small brush, and it turned out that damage to the delicate Albarran mechanism is often caused thereby. Moreover, because of the integrated construction of the Albarran mechanism, any necessary repair thereof is time-consuming and expensive, as the entire encapsulated head, which also includes the lens, has to be exposed and, after the Albaran mechanism has been repaired, the head has to be encapsulated again.
In another endoscope known from the document JP Sho 62 42 606, the Albarran mechanism can be screwed off the endoscope head and can be removed after the traction wire of the Bowden wire device has been released at the proximal end by loosening a screw connection. After a distal stop plate has been loosened by screwing it off, the sheathing of the Bowden wire device can be pulled out.
This kind of loosening of the connection, however, requires technically skilled personnelxe2x80x94for reasons of liability, this is usually even done by a maintenance engineer of the company that produces the endoscopexe2x80x94, as such complex loosening of the connections can neither be expected from unskilled operating personnel such as a doctor""s assistant nor can it be done by him or her.
If this endoscope should not have any seals to ensure that no contaminating material will enter at the distal end thereof, the endoscope would have to be cleaned after each use by loosening all the above-mentioned connections. As it is necessary to have this done by technically skilled personnel, this type of cleaning is complicated, expensive and time-consuming, and is thus not practical in medical working routine.
This problem was solved by an endoscope described in the document DE 196 27 016 C1; here, a support device for the Albarran mechanism can be removed from the head of the endoscope in the longitudinal direction by the operating personnel by loosening a quick-acting clamping device for the traction wire of the Bowden wire device, so both the support device, the traction wire of the Bowden wire device, the sheathing of the Bowden wire device, and the channel of the Bowden wire device can be cleaned easily by the operating personnel.
In practice, however, it turned out that a quick-acting clamping device which did not exist in known prior art was difficult to realize, as the necessary accuracy when moving a mechanism located at the distal end requires that the working area of the distal mechanism and the operating mechanism at the proximal end for this purpose always remains the same, irrespective of the number of loosening and attachment actions.
Thus, the object of the present invention is to provide an endoscope with a quick-acting clamping device which guarantees the required accuracy when moving a mechanism located at the distal end irrespective of the number of loosening and attachment actions, including the removal of the distal mechanism, pulling out the traction wire of the Bowden wire device and the sheathing thereof by the operating personnel, and easy loosening of the mechanism located at the distal end for cleaning purposes by the operating personnel.
According to the invention, this object is achieved by the features of claim 1.
By providing a quick-acting clamping device in the form of a quick-acting closure, with a locking position for loosening and attaching the traction wire of a Bowden wire device by means of an attachment unit, it is ensured that the attachment is always effected in the same exact position regarding the longitudinal displacement of the traction wire of the Bowden wire device. Hereby, the working area for the entire operating mechanism (both proximal and distal) for a mechanism to be operated, particularly an Albarran mechanism, remains the same at the distal end irrespective of the number of previous attachment and loosening actions.
At the same time, by providing a second quick-acting closure, it is possible for the operating personnel to easily remove the mechanism located at the distal end and to pull out the traction wire of the Bowden wire device. Thus, each time the endoscope has been used, it can easily be cleaned as necessary by the operating personnel. For this purpose, by loosening the first and the second quick-acting closures, the endoscope can quickly and easily be disassembled into the components traction wire of the Bowden wire device and distal mechanism; due to the fact that sealing elements are not necessary, all the contaminated parts as well as the inner space of the sheathing of the Bowden wire device can easily be cleaned by the operating personnel themselves, using e.g. effective cleaning andxe2x80x94as the case may bexe2x80x94sterilization methods such as ultrasonic waves, an autoclave, etc.
Furthermore, in case of wear, damage, etc., the Albarran mechanism can easily be replaced with a new Albarran mechanism by the operating personnel, potentially with further developments of Albarran mechanisms or other types thereof, without a time-consuming and expensive disassembly of the endoscope head and the proximal end of the endoscope by a technician being necessary.
If an individual channel of the Bowden wire device is formed inside the endoscope, as described in the document DE 196 27 016 C1, it is possible to additionally pull out the sheathing of the Bowden wire device and the traction wire of the Bowden wire device either at least partially or entirely. This further facilitates and improves the loosening of the Albarran mechanism and the support device and thus the cleaning of the Bowden wire device because now, with the separable connection for the traction wire of the Bowden wire device at the proximal end in the form of a first quick-acting closure, the entire Bowden wire device, i.e. the traction wire of the Bowden wire device and the sheathing thereof, can be pulled out either together or one after the other by at least a certain length or even completely.
Here, it is advantageous if, as described above, the sheathing of the Bowden wire device is not fixedly attached to the endoscope at the proximal and/or the distal end thereof, e.g. by a screw connectionxe2x80x94although this is possible in principalxe2x80x94, but only limited in its movement in the longitudinal direction via a proximal and a distal stop, respectively. Here, the detachable support device may form the distal stop, so after loosening the traction wire of the Bowden wire device by the first quick-acting closure and after removing the support device by loosening the second quick-acting closure, it is possible to pull out not only the traction wire of the Bowden wire device, but also the sheathing of the Bowden wire device at the distal end in the longitudinal direction.
In an embodiment of the invention, the Albarran mechanism is located in a support device, which may be configured e.g. as a slide. This slide comprises guide elements which cooperate with complementary elements at the head of the endoscope in such a way that they prevent a lateral movement, i.e. perpendicularly to the direction of movement of the traction wire of the Bowden wire device. These guide elements may e.g. be configured as cylindrical projections which engage corresponding recesses at the head of the endoscope in the longitudinal direction, i.e. the direction of movement of the traction wire of the Bowden wire device. These projections may also be hollow cylindrical extensions of the channels present in the head of an endoscope, such as the channel of the Bowden wire device and/or the working channel for instruments to be introduced, which engage recesses in the distal end of the channels which have a correspondingly enlarged inner periphery. Of course, lateral guides extending in the longitudinal direction, such as a dovetail guide, are also conceivable. Advantageously, wrong insertion by the operating personnel and corresponding damage caused are avoided thereby, as the direction of insertion, which has to be effected substantially in the longitudinal direction because of the relatively rigid traction wire of the Bowden wire device, is predetermined thereby.
In a further embodiment of the invention, both the movement of the support device and the movement of the sheathing of the Bowden wire device in the longitudinal direction are prevented after insertion by the second quick-acting closure, having e.g. the form of a snap-fit or locking closure. Hereby, even in case of a sheathing of the Bowden wire device which is only fixed in the longitudinal direction in the form of proximal and distal stops or which is fixedly connected with the endoscope, it is possible to achieve an exact position of the traction wire of the Bowden wire device after insertion, with the Albarran mechanism or the Albarran lever being in its inoperative position. This inoperative position is reached automatically when the traction wire of the Bowden wire device is introduced into the sheathing of the Bowden wire device, due to the back pressure produced in the direction of the distal end; however, it can also be supported by a corresponding restoring spring at the Albarran lever.
In addition to the improved loosening of the Albarran mechanism and the support device and in addition to the advantages resulting therefrom, this embodiment of the invention also guarantees easier cleaning of the Bowden wire device and the channel of the Bowden wire device and of the areas which are otherwise very difficult to keep hygienically clean and sterile by the operating personnel, which cleaning has to be effected each time the endoscope has been used for reasons of hygiene.
In a further embodiment, the proximal end of the traction wire of the Bowden wire device is stiffened e.g. by soldering or by brazing, without increasing the outer periphery thereof. Advantageously, due to the increased resistance to pressure, this helps to avoid that the effect of attachment in the first quick-acting closure is impaired e.g. by squeezing, fraying out or destroying the end of the wire in any other way, without an undesired increase in the inner diameter of the sheathing of the Bowden wire device and also of a potentially existing additional channel of the Bowden wire device being necessary for introducing the traction wire of the Bowden wire device from the distal end.
In an advantageous embodiment of the invention, the arrested locking position and loosening or connecting the traction wire of the Bowden wire device with the first quick-acting closure can be achieved or effected simultaneously by means of a single operating element. For this purpose, the operating element is configured e.g. as a turning knob which comprises a characteristic guide line effective in the longitudinal direction and, in a plane perpendicular to this direction, an attachment mechanism affecting the wire for arresting. The attachment mechanism may be configured as an eccentric or cam rotatable in this plane, which affects the proximal end of the traction wire of the Bowden wire device directly or via a lever which has been prestressed by the force of a spring. Here, the characteristic guide line may be configured e.g. as a recess extending at the outer periphery and tapering in the direction of rotation towards the locking position, which cooperates with a peg which is fixedly arranged at the endoscope. By contrast, the end position xe2x80x9cworking areaxe2x80x9d in the opposite direction of rotation is formed by an opening which widens this recess in the longitudinal direction so that a peg fixedly arranged at the endoscope can be pivoted into the characteristic guide line or out of the same through this opening.
In a particularly advantageous embodiment of the invention, the quick-acting closure, which is configured e.g. as a pivotable flap, can be pivoted in one direction opposite to the distal end and beyond the working area, with the result that the traction wire of the Bowden wire device will slip through in the attachment unit by the length of this pivoting movement.
This may serve to exert a higher prestress onto the Bowden wire device in the direction of pushing if the shaft of the endoscope is in a position in which it is entwined and bent to a large extent, resulting in an imperfect restoring effect of the Albarran mechanism in its inoperative position. Thus, advantageously, the reduced working area occurring in known endoscopes in this position can be compensated, so the function and the mobility of the Albarran mechanism are not limited even in such a position. Instead of the action of slipping through, it is of course also possible to loosen the attachment unit in the quick-acting closure and to close it in a position differing from the former position or in a locking position, as described above. This makes it possible to, in a way, grasp the traction wire of the Bowden wire device again in both directions during an operation, so it is advantageously possible to react on working areas changed by extreme situations.
If the quick-acting closure which is arranged on the outside or is at least accessible from outside is pivoted in the longitudinal direction of the traction wire of the Bowden wire device, which means that it is merely displaced, the end of the traction wire of the Bowden wire device is advantageously not additionally subjected to a bending load. Thus, a potential breakage of the end of the traction wire of the Bowden wire device, particularly of a stiffened end, can be prevented.
If the quick-acting closure is configured as a clamping device which is displaceable in the longitudinal direction of the traction wire of the Bowden wire device, e.g. in the form of a slide with a clamping gripper which can be clamped or can be opened and closed by a clamping element, the end of the traction wire of the Bowden wire device is subjected to a force acting to the inside in an area within the clamping gripper from several sides distributed over the periphery or along the entire periphery or is clamped thereby. This has the advantage that damage resulting from a deformation or squeezing of a too small area or spot and/or a deformation of the cross-section of the traction wire from one side can be avoided.
What all the embodiments according to the invention have in common are advantages such as the exertion of a prestress, i.e. the change of the working area and the improved possibilities of cleaning by loosening and, as the case may be, disassembling of the quick-acting closures, removing the head of the endoscope and/or pulling out the Bowden wire device and, as the case may be, disassembling the same, and even a complete disassembly of all these parts by the operating personnel. Furthermore, the operating personnel themselves can easily attend to the maintenance, repair and exchange of individual parts, which could formerly only be done by a technician.
Further advantageous embodiments of the invention are apparent from the subclaims.